TYPO3 Core

See attached screenshot.

IE6 needs a width for those elements, the problem is that they can change their width depending on f.e. username length, localized labels, FE preview on/off for workspaces.

edit: solution could be to redirect IE6 user to alt_main.php

Unfortunately there are quite a lot of people which use IE6. Imagine video tutorial showing the new features of TYPO3 4.2 and the frustration of IE6 users watching these videos and having no clue why they can't use it...
Thus, I tend to have a new backend for all current browsers and versions. Just my two cents.

of course! we "just" need to find a solution ;-)

maybe calculating the width from the counted chars or so =/ (hack)

There is no need to define the with the solution is quite simple.
Set the height of all inner li divs to auto instead of 23px.

I attached a simple sample to play arround with
and a screenshot of the backend with height set to auto.

here's a patch

thanks Nikolas!

fixed in trunk